Staedter



No. 6l5,524. Patented mp, 1898. F. BRANDSTAEDTER.

SCREENING 0R BULTING MACHINE. 1

(Application filed Nov. 26, 1897.)

(No Model.)

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m5 Nonms PETERS co. mo'muwcz.v WASHINGTON, u. a

UNITED. STATES PATENT OFFICE.

FRIEDRICH BRANDSTAEDTER, OF LOUVAIN, BELGIUM.

SCREENING OR BOLTING MACHINE.

SPECIFICATION forming part of Letters Patent No. 615,524, dated December6, 1898. Application filed November 26, 1897. Serial No. 659.884. (Nomodel.)

To all whom it may concern:

Be it known that I, FRIEDRICH BRAND- STAEDTER, a subject of the King ofBelgium, residing at Louvain, Belgium, have invented certain new anduseful Improvements in Screening or Bolting Machines, (for which LettersPatent have been obtained in Belgium, No. 126,283, dated February 27,1897; in England, No. 502, dated April 10, 1897; in Austria, No.47/2,74=9, dated July 20, 1897; in Hungary, No. 9,2at6, dated August18,1897; in Spain, No. 20,840, dated June 22, 1897, and in France, No.264.345. dated Februarv 23. 1897;) and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled inthe art to which it appertains to make anduse the same, reference being had to the accompanying drawings, and toletters and figures of reference marked thereon, which form a part ofthis specification.

In screening or bolting machines, especially in machines for screeningfinely-pulverized materials, as middlings or flour from finelygroundcereals, the meshes of the screen or bolt cloth become readily choked bymaterial lodging therein, as is well known, and various means have beenemployed and suggested for the purpose of avoiding this. Among others ithas been proposed to so mount the cloth that at each movement of thescreen or bolt the cloth is alternately slackened and stretched in onedirection-namely, lengthwise of the bolt-whereby a shaking motion in adirection perpendicular to the motion of the screen or bolt is impartedto the cloth and the meshes thereof more or less elongated or drawn outin one direction. This and other means hitherto resorted to have beenbut partially successful in preventing the choking ing therein. Thecontraction and expansion of the meshes in different directions are ofcourse due to variations in diiferent directions in the tension of thescreen or bolt cloth or at different points of its surface, theinvention being of special advantage when applied to horizontallyoscillating, reciprocating, or gyrating screens or bolts. Anoscillatory, reciprooating, or gyrating motion is or may be imparted tothe bolt by mechanism so well known as to require neither descriptionnor illustration.

The invention has for its further object to utilize the devices forpreventing the screen or bolt cloth meshes from choking up as a meansfor forwarding the screened material along a second screen or bolt clothor along a collecting board or table.

Referring to the accompanying drawings, Figures 1 and 2 are top planviews of a screen or bolt, illustrating different arrangements of thedevices for keeping the cloth meshes clear. Fig. 3 is a cross-section online a: m of Fig. 1. Figs. 4. and 5 are cross-sectional views of ascreen or bolt, illustrating modifications in the construction of thedevices for keeping the cloth-meshes clear. Fig. 6 is a fragmentarytopplan view of a portion of ascreen or bolt in which the devices forkeeping the cloth-meshes clear are utilized to forward-the materialpassing through said screen along a second screen or along acollecting-board. Fig. 7 is a longitudinal section on line y y of Fig.6. Fig. 8 is a cross-section on line .2 z of said Fig. 7, and Fig. 9 isalso a cross-section illustrating a modification in the construction ofthe devices for keeping the meshes of the screen or bolt cloth clear andfor forwarding the material passing therethrough along a second screenor collecting-board.

up of the screen or bolt cloth meshes.

The object of this invention is to provide simple means whereby thecloth is alternately slackened and stretched in different directions-4.e., bot-h lengthwise and crosswise or in other directions, as in planesdiagonal to the surface of the bolt, whereby the meshes are contractedand again expanded first in one'direction or in the plane of twoopposite sides of the mesh and then in an opposite direction or in theplane of the other two sides or in the direction of the angles of themeshes, so that the ground material passing through said meshes iseffectually prevented from lodg- As hereinabove stated, the inventionconsists, essentially, in varying the tension of a screen or bolt clothatdifferent points of its surface by imparting to such cloth at suchdifferent points alternating slackening and stretching movements indirections at right angles to each other, either crosswise andlongitudinally or diagonally of the boltcloth. Thus, for instance, thescreen or bolt cloth at a given point of its surface may partake of themovements of the screen or bolt in a given direction, while at anotherpoint of its surface the cloth is caused to move in difierout oropposite directions, whereby variations of tension at different pointsare produced naturally in such manner that at certain points the clothwill be slackened and at others stretched in different directions. ThisI attain by connecting with the cloth at different points of its surfacebodies sufficiently heavy relatively to the cloth, and instead ofallowing them to partake of the general movements of the bolt or screenI compel them to move in definite directions, differing from orcorresponding with and differing from the said general direction ofmotion of the screen or bolt. To attain these results, the bolt-cloth isnot stretched taut on the bolt-frame, but is more or less slack, as maybe readily cornprehended. v

Although the arrangements of the Weights is symmetrical, generallyspeaking, yet this arrangement can be varied. Thus, for instance, inFig. 1 I have shown a screen or bolt B, in which the series ofweights-as, for instance, small blocks of wood b Z -are secured to theunder face of the cloth a, so that the series of blocks 2) will havemotion longitudinally of the cloth on wires or rods 7', secured to thescreen or bolt frame, while the series of blocks 1), threaded on wiresor rods r, have motion transversely of the screen or bolt. Inasmuch asthe rods or wiresr and r are rigidly connected with the ends and sides,respectively, of said screen or bolt frame B, the blocks I) and 1)instead of partaking of the oscillating movements of the screen or boltwill receive motion longitudinally and crosswise of the bolt-cloth a,respectively, and as said blocks are rigidly connected with the saidcloth and are also free to vibrate on their rods the tension of thecloth will be varied at as many points as said cloth is connected withsaid blocks, or, in other words, the cloth will be alternately slackenedand drawn taut at many points of its surface and in differentdirections, according to the direction of motion of the bolt or screen,so that the meshes of the cloth thereof assume a rhomboidal form whensaid cloth is drawn taut, as indicated in dotted lines in Fig. 1. If, onthe other hand, the supporting wires or rods r r are.

arranged in diagonally-intersecting planes, the meshes of the cloth arealternately enlarged and contracted at numerous points, according to thedirection of oscillation of the screen or bolt frame B. Of course itwill be readily seen that the same results can be obtained with a bolthaving a gyrating or a reciprocating motion.

Instead of threading the blocks 17 and 1) upon their respective wires orrods 1" and 0* said blocks may be arranged so as to have a rockingmotion on substantially-fixed points on said wires or rods, and to thisend 1 provide the blocks 19 with a knife-edge bearing 5 Fig. 4E, andwith a balancing-weight w, the variations. in the tension of the clothoat different points being here due to the oscillating or rocking motioninstead of the to-and-fro sliding motion of the blocks. The same resultsare obtained by combining the sliding and rocking movements of theblocks by simply providing said blocks b with two knifeedge bearings Z917 between which the wire or rod 1' or r passes, Fig. 5, whereby thefriction between the blocks and their supports is at the same timereduced to a minimum.

It is furthermore obvious that instead of arranging the blocks 1) b onthe under side of the cloth 0 they may with like results be arranged onthe upper face of such cloth.

As previously stated, the invention comprises the utilization of themore or less heavy bodies or blocks as a means for forwarding thematerial passing through the screen or bolt cloth 0 onto a screen orcollecting or gathering board 0' below. To this end the transverse rowsof blocks 12 are made of such length that their lower edges will lieproximate to said lower screen or gatheringboard a, and said blocks areso connected with the cloth 0 as that the end blocks of the several rowslie close to one of the side barsas, for instance, the right-hand sidebar 2 of the screen or bolt frame B, Figs. 6 and 8- while the edges ofsaid blocks 19 facing the opposite side bar 3 of said frame may bebeveled, as shown in Fig. 9, to increase the dis tance or space betweeneach two blocks when this becomes necessary or when the meshes of thecloth are such as to allow comparatively large quantities of thematerial to pass therethrough; but when the meshes of the cloth are veryfine this beveling of the edges of the blocks is not necessary.

It is evident that when the bolt or screen has a circular oscillatingmotion in one direction the material on the lower screen or thegathering-board 0 will partake of this movement and will be thrown orcaused to move, say, from the side 2 of the screen or bolt frame to theopposite side 3, a portion of the material moving lengthwise of thelower screen through the passages formed between the blocks 1). When, onthe contrary, the screen or board 0 oscillates in an opposite direction,the material. between the rows of blocks is moved back toward the side 2of the screen or bolt frame B, but cannot move along said side becauseof the proximity there to of the end blocks of the transverse rows ofsuch and because there is a greater number of passages on one side ofthe longitudinal center of the screen or bolt than on the other, so thata greater portion of the ma terial is caused to move along 0' in onedirection than in the other, whereby said ma terial is graduallyforwarded from the feed end of the bolt to the discharge-throat 4 of thecloth or board 0, the tailings passing from the cloth 0 to a separatedischargethroat 5, Figs. 1 and 2, or, in other words, the quantity ofmaterial moving in the direction of said delivery end 4 is greater thanthe quantity of material moving in an opposite direction, as will bereadily understood.

The weightsc'. 6., the blocks 1) b, &c.-

IIC.

may be secured to the bolt-cloth c in any desired manner, as bycementing, gluing, or tacking.

In bolts of considerable superficial area the cloth will be subjected togreat strain at different points in different directions, which mightresult in injury. This may be avoided by interposing between two or morerows of weights strips 6, secured to the bolt-frame, and to which thecloth 0 is likewise secured.

Having thus described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is-

1. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion; of means adapted to im part to said clothhorizontal to-and-fro move ments in different planes at different pointsof its surface when the bolt is in motion, for the purpose set forth.

2. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of means adapted to act upon the cloth toalternately stretch and slacken the same in didercnt planes at differentpoints of-its surface when the bolt is in motion, for the'purpose setforth.

3. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of means connected with the cloth atdifferent points of its surface and adapted to alternately stretch andslacken the same in planes angular to one another when the bolt is inmotion, for the purpose set forth.

4. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of means for alternately slackening andstretching the cloth at different points of its surface in planesangular to one another, for the purpose set forth.

5. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of weights arranged to act upon the clothat different points of its surface to alternately slacken and stretchthe cloth in planes angular to one another, for the purpose set forth.

6. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of weights attached to the cloth andadapted to alternately slacken and stretch the same at different pointsof its surface and in planes angular to one another, for the purpose setforth.

7. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of means for alternately slackening andstretching the cloth in directions differing from each other and fromthe direction of motion of the screen or bolt, for the purpose setforth.

8. The combination with the cloth of a screen or bolt adapted to receivea screening or bolting motion, of means connected with said cloth andadapted to alternately slacken and stretch the same at different pointsof supports rigidly connected with the screen or bolt frame, for thepurpose set forth.

10. The combination with a screen or bolt, of weights attached to thecloth at different points of its surface, and supports for and on whichsaid weights have sliding and oscillating motion, said supports rigidlyconnected with the screen or bolt frame, for the purpose setforth.

11. The combination with a screen or bolt, and rods rigidly connectedwith its frame and arranged in intersecting planes, of weights havingsliding and rocking motion on said rods, said weights attached to thebolt cloth at different points of its surface, for the purpose setforth.

12. The combination with a screen or bolt, and a receiver for thescreened or bolted material secured to the bolt-frame below thebolt-cloth, of weights attached to the under side of the cloth withtheir free ends close to the surface of said receiver, said Weightsarranged in transverse rows so as to leave a space between each twoweights and between the last of a row and one side of the boltframe,said weights adapted to receive a vibrating motion in one direction anda to-andfro motion in a direction at rightangles thereto, for thepurpose set forth.

13. The combination with ascreen or bolt, and a receiver for thescreened or bolted ma terial secured to the bolt-frame below the cloth,and rods secured to said frame in transverse ro'ws between the cloth andreceiver; of plate-like weights attached to the under side of the clothand supported from and having motion on said rods, said weights arrangedto leave a space between them and between the last of a row and one sideof the boltframe, for the purposes set forth.

14. The combination with a screen or bolt and a receiver for thescreened or bolted material secured to the bolt-frame below the cloth,and rods secured to said frame in transverse rows between the cloth andreceiver; of plate-like weights attached to the under side of the clothand supported from and having a to-and-fro and an oscillating motion onsaid rods, said weights arranged to leave a space between them andbetween the last of a row and one side of the bolt-frame, for thepurposes set forth.

In testimony that I claim the foregoing as my invention I have signed myname in pres ence of two subscribing witnesses.

FRIEDRICH BRANDSTAEDTER.

\Vituesscs:

HENRI RASTODI, EDOUARD LABAUN.

